The first wave of deposition notices went out Wednesday in federal lawsuit by a former Minnesota legislative staff member fired after his affair with the then-Senate majority leader.

Attorneys for ex-staffer Michael Brodkorb, who was a senior communications aide for Senate Republicans, filed court papers to depose three ex-senators and one sitting senator as they try to make the case his firing amounted to gender discrimination. Also slated for an early June deposition is former Secretary of the Senate Cal Ludeman.

Brodkorb's case against the Senate argues his firing from his extramarital affair with then-Sen. Amy Koch subjected him to different treatment than female Senate staffers who had affairs.

The politicians listed are all Republican. They are current Sen. David Senjem of Rochester and former Sens. Claire Robling of Jordan, Chris Gerlach of Apple Valley and Geoff Michel of Edina.

Senjem, who replaced Koch as majority leader, said he was expecting to be called on for sworn testimony. He said he has little to add about what transpired than what he has already said publicly since the December 2011 dismissal of Brodkorb.

"I welcome total interrogation," Senjem said. "I don't expect there will be too much new under the covers in my life."